I was trying to learn Linux, and a guide told me to use Virtual Box and CentOS since CentOS is similar to Red Hat. However, I encountered some CPU issue with my machine, so I wanted to try running a different distribution to learn from. I downloaded Ubuntu Kylin, and it won't appear in the Virtual Box tool when I search for it. I believe that it is because Kylin is a Disk Image, and CentOS is in the correct format of a Virtual Disk Image. Is there a simple way to convert the Disk Image without installing some sort of program that I'm unfamiliar with?
If you can find a Virtual Machine image (ovf or ova) for CentOS, you can 'Import Appliance' and follow the steps. However, most people download the CentOS ISO CD image, then create a new Virtual Machine in VirtualBox. Next you would "load" the ISO into the Virtual Machine CD drive, and on boot go through the OS install process (installing from the ISO/CD to the VM hard drive in Virtual Box).